Effects of Geomagnetic effect on Sub-ionospheric VLF-LF Signals Propagation
Abstract
Abstract: To investigate the effect of geomagnetic storm on subionospheric VLF-LF signal propagation, we analyze the variation in amplitude of VLF-LF signal using advanced complex continuous wavelet transform techniques. We analyze the VLF signal transmitted form ICV (20.27 kHz) located at Isola di Tavolara (40.55o N, 9.430 E), Italy and DH038 (23.40 kHz) Rhauderfehn (53.040 N, 7.340 E) Germany and one LF signal transmitted form NRK (37.50 kHz) transmitter located at Grindavik (63.510 N, 22.280 E), Iceland. We observed significant absorption in amplitude of these signals during the geomagnetic storm compared to their ambient values for the same period during the adjacent 7 days. The signal strength along their propagation paths was controlled by the storm associated decrease in ionization in the D-region of the ionosphere. Waveguide mode theory calculations show that the elevation of the height of lower ionosphere boundary of Earth-ionosphere waveguide was significantly decreased during this period. Key words: Subionospheric VLF-LF propagation, Complex Wavelet Transform, Geomagnetic activity and Earth-ionosphere waveguide
- Publication:
-
40th COSPAR Scientific Assembly
- Pub Date:
- 2014
- Bibcode:
- 2014cosp...40E3173S